Metallocene-supported catalyst and method of preparing polyolefin using the same

ABSTRACT

Provided are a novel metallocene-supported catalyst and a method of preparing a polyolefin using the same. The metallocene-supported catalyst according to the present disclosure may be used in the preparation of polyolefins, it may have excellent activity and excellent reactivity with comonomers, and it may prepare olefinic polymers having a high molecular weight and a low molecular weight.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on, and claims priority from, KoreanPatent Application No. 10-2014-0179763, filed on Dec. 12, 2014, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present disclosure relates to a novel metallocene-supported catalystand a method of preparing a polyolefin using the same.

BACKGROUND OF THE INVENTION

Olefin polymerization catalyst systems may be divided into Ziegler-Nattaand metallocene catalysts, and these highly active catalyst systems havebeen developed in accordance with their characteristics. TheZiegler-Natta catalyst has been widely applied to commercial processessince it was developed in the 1950's. However, since the Ziegler-Nattacatalyst is a multi-active site catalyst in which a plurality of activesites are mixed, it has a feature that a resulting polymer has a broadmolecular weight distribution. Also, since a compositional distributionof comonomers is not uniform, there is a problem that it is difficult toobtain desired physical properties.

Meanwhile, the metallocene catalyst includes a main catalyst having atransition metal compound as a main component and an organometalliccompound cocatalyst having aluminum as a main component. Such a catalystis a single-site catalyst which is a homogeneous complex catalyst, andoffers a polymer having a narrow molecular weight distribution and auniform compositional distribution of comonomers, depending on thesingle site characteristics. The stereoregularity, copolymerizationcharacteristics, molecular weight, crystallinity, etc. of the resultingpolymer may be controlled by changing a ligand structure of the catalystand polymerization conditions.

U.S. Pat. No. 5,032,562 discloses a method of preparing a polymerizationcatalyst by supporting two different transition metal catalysts on onesupport. This catalyst is prepared by supporting a titanium (Ti)-basedZiegler-Natta catalyst which produces a high molecular weight polymerand a zirconium(Zr)-based metallocene catalyst which produces a lowmolecular weight polymer on one support, and results in a bimodalmolecular weight distribution. This catalyst is disadvantageous in thatthe supporting procedure is complicated and morphology of polymers ispoor due to a cocatalyst.

U.S. Pat. No. 5,525,678 discloses a method of using a catalyst systemfor olefin polymerization, in which a metallocene compound and anon-metallocene compound are simultaneously supported on a support torealize simultaneous polymerization of a high molecular weight polymerand a low molecular weight polymer. However, there are disadvantagesthat the metallocene compound and non-metallocene compound must beseparately supported and the support must be pretreated with variouscompounds for supporting.

U.S. Pat. No. 5,914,289 discloses a method of controlling a molecularweight and a molecular weight distribution of polymers using metallocenecatalysts which are respectively supported on supports. However, a largeamount of solvent and a long period of time are required to prepare thesupported catalysts, and a process of supporting metallocene catalystson the respective supports is troublesome.

Korean Patent Application No. 2003-12308 discloses a method ofcontrolling molecular weight distributions of polymers, in which thepolymerization is performed while changing a combination of catalysts ina reactor by supporting a dinuclear metallocene catalyst and amononuclear metallocene catalyst on a support together with anactivating agent. However, this method has limitations in simultaneouslyrealizing the characteristics of respective catalysts. In addition,there is a disadvantage that the metallocene catalysts depart from asupported component of the resulting catalyst to cause fouling in thereactor.

Meanwhile, a slurry process of employing the existingmetallocene-supported catalyst has a problem of low productivity due tolow density and low bulk density (BD) of a produced polymer powder.

Accordingly, to solve the above drawbacks, there is a continuous demandfor a method of preparing polyolefins with desired physical propertiesby easily preparing a metallocene-supported catalyst having excellentactivity.

DETAILS OF THE INVENTION Objects of the Invention

To solve the above problems in the prior arts, the present disclosureprovides a metallocene-supported catalyst which has excellent activityand productivity and is able to prepare polyolefins having a highmolecular weight and a low molecular weight, a method of preparing apolyolefin using the same, and a polyolefin prepared by using the same.

Means for Achieving the Object

The present disclosure provides a metallocene-supported catalystincluding one or more metallocene compounds represented by the followingChemical Formula 1 or Chemical Formula 2, a cocatalyst compound, and asupport:

wherein, in Chemical Formula 1, R₁ and R₂, and R₅ and R₆, are the sameas or different from each other, and are each independently hydrogen ora C1 to C20 alkyl group;

R₃ and R₄, and R₇ and R₈, are the same as or different from each other,and are each independently hydrogen or a C1 to C20 alkyl group, or twoor more neighboring groups of R₃ and R₄, and R₇ and R₈, are connected toeach other to form a substituted or unsubstituted aliphatic or aromaticring;

Q is a Group 4 transition metal; and

R₉ and R₁₀ are the same as or different from each other, and are eachindependently a C1 to C20 alkylate group,

wherein, in Chemical Formula 2, M is a Group 4 transition metal;

B is carbon, silicon, or germanium;

Q₁ and Q₂ are the same as or different from each other, and are eachindependently hydrogen, a halogen, a C1 to C20 alkyl group, a C2 to C20alkenyl group, a C6 to C20 aryl group, a C7 to C20 alkylaryl group, a C7to C20 arylalkyl group, a C1 to C20 alkoxy group, a C2 to C20alkoxyalkyl group, a C3 to C20 heterocycloalkyl group, or a C5 to C20heteroaryl group;

X₁ and X₂ are the same as or different from each other, and are eachindependently a C1 to C20 alkylate group; and

C₁ and C₂ are the same as or different from each other, and are eachindependently represented by any one of the following Chemical Formula3a, Chemical Formula 3b, Chemical Formula 3c, and Chemical Formula 3d,provided that one or more of C₁ and C₂ is represented by ChemicalFormula 3a,

wherein, in Chemical Formulae 3a, 3b, 3c, and 3d, R₁ to R₂₈ are the sameas or different from each other, and are each independently hydrogen, ahalogen, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C1 to C20alkylsilyl group, a C1 to C20 silylalkyl group, a C1 to C20 alkoxysilylgroup, a C1 to C20 ether group, a C1 to C20 silylether group, a C1 toC20 alkoxy group, a C6 to C20 aryl group, a C7 to C20 alkylaryl group,or a C7 to C20 arylalkyl group,

R′₁ to R′₃ are the same as or different from each other, and are eachindependently, hydrogen, a halogen, a C1 to C20 alkyl group, a C2 to C20alkenyl group, or a C6 to C20 aryl group, and

two or more neighboring groups of R₁ to R₂₈ are connected to each otherto form a substituted or unsubstituted aliphatic or aromatic ring.

Further, the present disclosure provides a method of preparing apolyolefin, the method including polymerizing olefinic monomers in thepresence of the above catalyst.

In addition, the present disclosure provides a polyolefin which isprepared according to the above preparation method.

Effects of the Invention

A metallocene-supported catalyst according to the present invention maybe used in the preparation of polyolefins, and it may remarkably improvesolubility of a precursor compound, have excellent activity andexcellent reactivity with comonomers, and prepare polyolefins having ahigh molecular weight and a low molecular weight.

Particularly, the metallocene catalyst compound of the presentdisclosure may exhibit high polymerization activity even when it issupported on a support, thereby preparing polyolefins having a highmolecular weight and a low molecular weight.

Furthermore, since the catalyst has a long lifetime, its activity may bemaintained even for a long residence time in a reactor.

DETAILED DESCRIPTION OF THE EMBODIMENT

Although the term “first”, “second”, etc. may be used herein to describevarious elements, these terms are only used to distinguish one elementfrom another.

Further, the terminology used herein is for the purpose of describingexemplary embodiments only and it is not intended to restrict thepresent invention. The singular forms are intended to include the pluralforms as well, unless the context clearly indicates otherwise. The term“include”, “equip”, or “have” is intended to specify the presence ofstated features, integers, steps, elements, or combinations thereof, butdoes not preclude the presence or addition of one or more otherfeatures, integers, steps, elements, or combinations thereof.

While the present invention is susceptible to various modifications andalternative forms, specific embodiments will be illustrated anddescribed in detail as follows. It should be understood, however, thatthe description is not intended to limit the present invention to theparticular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

Hereinafter, the present disclosure will be described in more detail.

A metallocene-supported catalyst according to the present disclosure ischaracterized by including one or more metallocene compounds representedby the following Chemical Formula 1 or Chemical Formula 2, a cocatalystcompound, and a support:

wherein, in Chemical Formula 1, R₁ and R₂, and R₅ and R₆, are the sameas or different from each other, and are each independently hydrogen ora C1 to C20 alkyl group;

R₃ and R₄, and R₇ and R₈, are the same as or different from each other,and are each independently hydrogen or a C1 to C20 alkyl group, or twoor more neighboring groups of R₃ and R₄, and R₇ and R₈, are connected toeach other to form a substituted or unsubstituted aliphatic or aromaticring;

Q is a Group 4 transition metal; and

R₉ and R₁₀ are the same as or different from each other, and are eachindependently a C1 to C20 alkylate group,

wherein, in Chemical Formula 2, M is a Group 4 transition metal;

B is carbon, silicon, or germanium;

Q₁ and Q₂ are the same as or different from each other, and are eachindependently hydrogen, a halogen, a C1 to C20 alkyl group, a C2 to C20alkenyl group, a C6 to C20 aryl group, a C7 to C20 alkylaryl group, a C7to C20 arylalkyl group, a C1 to C20 alkoxy group, a C2 to C20alkoxyalkyl group, a C3 to C20 heterocycloalkyl group, or a C5 to C20heteroaryl group;

X₁ and X₂ are the same as or different from each other, and are eachindependently a C1 to C20 alkylate group; and

C₁ and C₂ are the same as or different from each other, and are eachindependently represented by any one of the following Chemical Formula3a, Chemical Formula 3b, Chemical Formula 3c, and Chemical Formula 3d,provided that one or more of C₁ and C₂ are represented by ChemicalFormula 3a,

wherein, in Chemical Formulae 3a, 3b, 3c, and 3d, R₁ to R₂₈ are the sameas or different from each other, and are each independently hydrogen, ahalogen, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C1 to C20alkylsilyl group, a C1 to C20 silylalkyl group, a C1 to C20 alkoxysilylgroup, a C1 to C20 ether group, a C1 to C20 silylether group, a C1 toC20 alkoxy group, a C6 to C20 aryl group, a C7 to C20 alkylaryl group,or a C7 to C20 arylalkyl group;

R′₁ to R′₃ are the same as or different from each other, and are eachindependently, hydrogen, a halogen, a C1 to C20 alkyl group, a C2 to C20alkenyl group, or a C6 to C20 aryl group; and

two or more neighboring groups of R₁ to R₂₈ are connected to each otherto form a substituted or unsubstituted aliphatic or aromatic ring.

Particularly, in the present disclosure, a particular substituent isintroduced into the transition metal in the metallocene compound ofChemical Formula 1 or Chemical Formula 2, thereby remarkably improvingsolubility of the metallocene compound and activity of a catalyst onwhich the metallocene compound is supported. R₉ and R₁₀ in ChemicalFormula 1 or X₁ and X₂ in Chemical Formula 2 may be a C1 to C20 andpreferably a C1 to C10 alkylate group.

With regard to the metallocene-supported catalyst according to thepresent disclosure, the substituents of Chemical Formula 1 or ChemicalFormula 2 are described in more detail as follows.

The C1 to C20 alkyl group may include a linear or branched alkyl group,and specifically, it may include a methyl group, an ethyl group, apropyl group, an isopropyl group, an n-butyl group, a tert-butyl group,a pentyl group, a hexyl group, a heptyl group, an octyl group, etc., butis not limited thereto.

The Group 4 transition metal may include titanium (Ti), zirconium (Zr),hafnium (Hf), etc., but is not limited thereto.

The C1 to C20 alkylate group may include a linear or branched alkylategroup, and specifically, it may include a methylate group, an ethylategroup, a propylate group, a pyvalate group, etc. Among them, thepyvalate group is applied to additionally produce active species andimprove solubility, thereby improving activity and productivity.

The C2 to C20 alkenyl group may include a linear or branched alkenylgroup, and specifically, it may include an allyl group, an ethenylgroup, a propenyl group, a butenyl group, a pentenyl group, etc., but isnot limited thereto.

The C6 to C20 aryl group may include a single ring aryl group or acondensed ring aryl group, and specifically, it may include a phenylgroup, a biphenyl group, a naphthyl group, a phenanthrenyl group, afluorenyl group, etc., but is not limited thereto.

The C5 to C20 heteroaryl group may include a single ring heteroarylgroup or a condensed ring heteroaryl group, and specifically, it mayinclude a carbazolyl group, a pyridyl group, a quinoline group, anisoquinoline group, a thiophenyl group, a furanyl group, an imidazolegroup, an oxazolyl group, a thiazolyl group, a triazine group, atetrahydropyranyl group, a tetrahydrofuranyl group, etc., but is notlimited thereto.

The C1 to C20 alkoxy group may include a methoxy group, an ethoxy group,a phenyloxy group, a cyclohexyloxy group, a tert-butoxyhexyl group,etc., but is not limited thereto.

The C1 to C20 alkylsilyl group may include a methylsilyl group, adimethylsilyl group, a trimethylsilyl group, etc., but is not limitedthereto.

The C1 to C20 silylalkyl group may include a silylmethyl group, adimethylsilylmethyl group (—CH₂—Si(CH₃)₂H), a trimethylsilylmethyl group(—CH₂—Si(CH₃)₃), etc., but is not limited thereto.

With regard to the metallocene compound according to the presentdisclosure, R₁ and R₂, and R₅ and R₆, in Chemical Formula 1 arepreferably a hydrogen, a methyl group, an ethyl group, a propyl group,an isopropyl group, an n-butyl group, a tert-butyl group, amethoxymethyl group, a tert-butoxymethyl group, a 1-ethoxyethyl group, a1-methyl-1-methoxyethyl group, a tert-butoxyhexyl group, atetrahydropyranyl group, or a tetrahydrofuranyl group, but is notlimited thereto.

Further, R₃ and R₄, and R₇ and R₈, of Chemical Formula 1 may be ahydrogen, a methyl group, an ethyl group, a propyl group, an isopropylgroup, an n-butyl group, a tert-butyl group, a methoxymethyl group, atert-butoxymethyl group, a 1-ethoxyethyl group, a1-methyl-1-methoxyethyl group, a tert-butoxyhexyl group, atetrahydropyranyl group, or a tetrahydrofuranyl group. Alternatively, R₃and R₄, or R₇ and R₈, are connected to each other to be a phenyl group,a cyclohexyl group, etc. However, R₃ and R₄, and R₇ and R₈, are notlimited to the above described substituents.

Meanwhile, in the present disclosure, when the compound of ChemicalFormula 3a having a particular substituent is applied to one or more ofC₁ and C₂ of Chemical Formula 2, it is possible to produce a polyolefinwith high activity and to maintain excellent copolymerization property.

Preferably, R₁ to R₂₈ of Chemical Formulae 3a, 3b, 3c, and 3d are eachindependently hydrogen, a halogen, a methyl group, an ethyl group, apropyl group, an isopropyl group, an n-butyl group, a tert-butyl group,a pentyl group, a hexyl group, a heptyl group, an octyl group, anethylene group, a propylene group, a butylene group, a phenyl group, abenzyl group, a naphthyl group, a halogen group, an ether group, atrimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, atributylsilyl group, a triisopropylsilyl group, a trimethylsilylmethylgroup, a dimethylether group, a tert-butyldimethylsilylether group, amethoxy group, an ethoxy group, or a tert-butoxyhexyl group, but are notlimited thereto.

Preferably, Q₁ and Q₂ of Chemical Formula 2 are hydrogen, a methylgroup, an ethyl group, a propyl group, an isopropyl group, an n-butylgroup, a tert-butyl group, a methoxymethyl group, a tert-butoxymethylgroup, a 1-ethoxyethyl group, a 1-methyl-1-methoxyethyl group, atert-butoxyhexyl group, a tetrahydropyranyl group, or atetrahydrofuranyl group, but are not limited thereto.

Preferably, B of Chemical Formula 2 is silicon, but is not limitedthereto.

Specifically, the metallocene compound of Chemical Formula 2 ischaracterized by including at least one C1 to C20 silylalkyl group suchas a trimethylsilyl methyl group in the substituent of Chemical Formula3a.

More specifically, an indene derivative of Chemical Formula 3a hasrelatively low electron density compared to an indenoindole derivativeor a fluorenyl derivative, and includes a silylalkyl group with largesteric hindrance. Therefore, due to steric hindrance effects andelectron density factors, the metallocene compound may polymerize anolefin polymer having a relatively low molecular weight with highactivity, compared to a metallocene compound having a similar structure.

Moreover, the indenoindole derivative which may be represented byChemical Formula 3b, the fluorenyl derivative which may be representedby Chemical Formula 3c, and the indene derivative which may berepresented by Chemical Formula 3d form a structure which is crosslinkedby a bridge and have an unshared electron pair which can act as a Lewisbase with respect to the structure of the ligand, thereby exhibitinghigh polymerization activity.

According to an embodiment of the present disclosure, a specific exampleof the functional group represented by Chemical Formula 3a may be acompound represented by any one of the following structural formulae,but the present disclosure is not limited thereto.

Further, a specific example of the functional group represented byChemical Formula 3b may be a compound represented by any one of thefollowing structural formulae, but the present disclosure is not limitedthereto.

A specific example of the functional group represented by ChemicalFormula 3c may be a compound represented by any one of the followingstructural formulae, but the present disclosure is not limited thereto.

Further, a specific example of the functional group represented byChemical Formula 3d may be a compound represented by any one of thefollowing structural formulae, but the present disclosure is not limitedthereto.

Additionally, a specific example of the metallocene compound representedby Chemical Formula 1 may be a compound represented by any one of thefollowing structural formulae, but the present disclosure is not limitedthereto.

The metallocene compound of Chemical Formula 1 may have excellentactivity and may polymerize olefinic polymers having a high molecularweight and a low molecular weight.

Further, a specific example of the metallocene compound represented byChemical Formula 2 may be a compound represented by the followingstructural formula, but the present disclosure is not limited thereto.

The metallocene compound of Chemical Formula 2 may have excellentactivity and may polymerize olefinic polymers having a high molecularweight and a low molecular weight.

According to an embodiment of the present disclosure, the metallocenecompound of Chemical Formula 2 may be obtained by connecting the indenederivative and a cyclopentadiene derivative with a bridge compound toprepare a ligand compound, and then carrying out metallation byinjecting a metal precursor compound thereto, but is not limited tothereto.

More specifically, for example, the indene derivative is reacted with anorganic lithium compound such as n-BuLi to preapare a lithium salt,which is mixed with a halogenated compound of the bridge compound, andthen this mixture is reacted to prepare a ligand compound. The ligandcompound or the lithium salt thereof is mixed with the metal precursorcompound, and this mixture is allowed to react for about 12 hrs to 24hrs until the reaction is completed, and then a reaction product isfiltered and dried under reduced pressure to obtain the metallocenecompound represented by Chemical Formula 1 or Chemical Formula 2. Amethod of preparing the metallocene compound of Chemical Formula 1 orChemical Formula 2 will be concretely described in examples below.

The metallocene-supported catalyst of the present disclosure may furtherinclude one or more of cocatalyst compounds represented by the followingChemical Formula 4, Chemical Formula 5, and Chemical Formula 6, inaddition to the above metallocene compound:

—[Al(R₃₀)—O]_(m)—  [Chemical Formula 4]

wherein, in Chemical Formula 4, each R₃₀ may be the same as or differentfrom each other, and are each independently a halogen, C1 to C20hydrocarbon, or halogen-substituted C1 to C20 hydrocarbon, and

m is an integer of 2 or more;

J(R₃₁)₃  [Chemical Formula 5]

wherein, in Chemical Formula 5, each R₃₁ is the same as defined inChemical Formula 4; and

J is aluminum or boron;

[E-H]⁺[ZA₄]⁻ or [E]⁺[ZA₄]⁻  [Chemical Formula 6]

wherein, in Chemical Formula 6, E is a neutral or cationic Lewis base;

H is a hydrogen atom;

Z is Group 13 element; and

Each A may be the same as or different from each other, and are eachindependently a C6 to C20 aryl group or a C1 to C20 alkyl group, ofwhich one or more hydrogen atoms is unsubstituted or substituted with ahalogen, C1 to C20 hydrocarbon, an alkoxy, or a phenoxy.

Examples of the compound represented by Chemical Formula 4 may includemethylaluminoxane, ethylaluminoxane, isobutylaluminoxane,butylaluminoxane, etc., and a more preferred compound ismethylaluminoxane.

Examples of the compound represented by Chemical Formula 5 may includetrimethylaluminum, triethylaluminum, triisobutylaluminum,tripropylaluminum, tributylaluminum, dimethylchloroaluminum,triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum,tripentylaluminum, triisopentylaluminum, trihexylaluminum,trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum,triphenylaluminum, tri-p-tolylaluminum, dimethylaluminummethoxide,dimethylaluminumethoxide, trimethylboron, triethylboron,triisobutylboron, tripropylboron, tributylboron, etc., and a morepreferred compound is selected from trimethylaluminum, triethylaluminum,and triisobutylaluminum.

Examples of the compound represented by Chemical Formula 6 may includetriethylammonium tetraphenylboron, tributylammonium tetraphenylboron,trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron,trimethylammonium tetra(p-tolyl)boron, trimethylammoniumtetra(o,p-dimethylphenyl)boron, tributylammoniumtetra(p-trifluoromethylphenyl)boron, trimethylammoniumtetra(p-trifluoromethylphenyl)boron, tributylammoniumtetrapentafluorophenylboron, N,N-diethylanilinium tetraphenylboron,N,N-diethylanilinium tetrapentafluorophenylboron, diethylammoniumtetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron,trimethylphosphonium tetraphenylboron, triethylammoniumtetraphenylaluminum, tributylammonium tetraphenylaluminum,trimethylammonium tetraphenylaluminum, tripropylammoniumtetraphenylaluminum, trimethylammonium tetra(p-tolyl)aluminum,tripropylammonium tetra(p-tolyl)aluminum, triethylammoniumtetra(o,p-dimethylphenyl)aluminum, tributylammoniumtetra(p-trifluoromethylphenyl)aluminum, trimethylammoniumtetra(p-trifluoromethylphenyl)aluminum, tributylammoniumtetrapentafluorophenylaluminum, N,N-diethylaniliniumtetraphenylaluminum, N,N-diethylaniliniumtetrapentafluorophenylaluminum, diethylammoniumtetrapentatetraphenylaluminum, triphenylphosphonium tetraphenylaluminum,trimethylphosphonium tetraphenylaluminum, tripropylammoniumtetra(p-tolyl)boron, triethylammonium tetra(o,p-dimethylphenyl)boron,tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetrapentafluorophenylboron, etc.

Preferably, alumoxane may be used, and more preferably, methylalumoxane(MAO), an alkyl alumoxane, may be used.

The metallocene-supported catalyst according to the present disclosuremay be prepared by a first method including 1) contacting themetallocene compound represented by Chemical Formula 1 or ChemicalFormula 2 with the compound represented by Chemical Formula 4 orChemical Formula 5 to obtain a mixture, and 2) adding the compoundrepresented by Chemical Formula 6 to the mixture.

Furthermore, the metallocene-supported catalyst according to the presentdisclosure may be prepared by a second method of contacting themetallocene compound represented by Chemical Formula 1 or ChemicalFormula 2 with the compound represented by Chemical Formula 4.

In the first method of preparing the supported catalyst, a molar ratioof the metallocene compound represented by Chemical Formula 1 orChemical Formula 2/the compound represented by Chemical Formula 4 orChemical Formula 5 is preferably 1/5000 to 1/2, more preferably 1/1000to 1/10, and most preferably 1/500 to 1/20. When the molar ratio of themetallocene compound represented by Chemical Formula 1 or ChemicalFormula 2/the compound represented by Chemical Formula 4 or ChemicalFormula 5 exceeds 1/2, there is a problem that the alkylating agent isvery small in quantity and the metal compound is not completelyalkylated. When the molar ratio is less than 1/5,000, the alkylation ofthe metal compound is accomplished, but there is a problem that thealkylated metal compound is not completely activated due to a sidereaction between the remaining excess alkylating agent and an activatorof Chemical Formula 5. Furthermore, a molar ratio of the metallocenecompound represented by Chemical Formula 1 or Chemical Formula 2/thecompound represented by Chemical Formula 6 is preferably 1/25 to 1, morepreferably 1/10 to 1, and most preferably 1/5 to 1. When the molar ratioof the metallocene compound represented by Chemical Formula 1 orChemical Formula 2/the compound represented by Chemical Formula 6exceeds 1, there is a problem that the activity of the preparedsupported catalyst is deteriorated because the activator is relativelysmall in quantity and the metal compound is not completely activated.When the molar ratio is less than 1/25, the activation of the metalcompound is completely accomplished, but there is a problem that cost ofthe supported catalyst is not economical or purity of the polymer to beprepared is decreased due to remaining excess activator.

In the second method of preparing the supported catalyst, a molar ratioof the metallocene compound represented by Chemical Formula 1 orChemical Formula 2/the compound represented by Chemical Formula 4 ispreferably 1/10000 to 1/10, more preferably 1/5000 to 1/100, and mostpreferably 1/3000 to 1/500. When the molar ratio exceeds 1/10, there isa problem that the activity of the prepared supported catalyst isdeteriorated because the activator is relatively small in quantity andthe metal compound is not completely activated. When the molar ratio isless than 1/10000, the activation of the metal compound is completelyaccomplished, but there is a problem that cost of the supported catalystis not economical or purity of the polymer to be prepared is decreaseddue to remaining excess activator.

As a reaction solvent used for preparing the supported catalyst, ahydrocarbon solvent such as pentane, hexane, heptane, etc., or anaromatic solvent such as benzene, toluene, etc. may be used.

Furthermore, the supported catalyst may include the metallocene compoundand the cocatalyst compound in the form of being supported on a support.

When the metallocene compound and the cocatalyst compound are used inthe form of being supported on a support, the metallocene compound maybe included in an amount of about 0.5 parts by weight to about 20 partsby weight and the cocatalyst may be included in an amount of about 1part by weight to about 1000 parts by weight, based on 100 parts byweight of the support. Preferably, the metallocene compound may beincluded in an amount of about 1 part by weight to about 15 parts byweight and the cocatalyst may be included in an amount of about 10 partsby weight to about 500 parts by weight, based on 100 parts by weight ofthe support. Most preferably, the metallocene compound may be includedin an amount of about 1 part by weight to about 100 parts by weight andthe cocatalyst may be included in an amount of about 40 parts by weightto about 150 parts by weight, based on 100 parts by weight of thesupport.

In the metallocene-supported catalyst of the present disclosure, aweight ratio of the total transition metals included in the metallocenecompound to the support may be 1:10 to 1:1000. When the support and themetallocene compound are included at the above weight ratio, an optimalshape may be obtained. Further, a weight ratio of the cocatalystcompound to the support may be 1:1 to 1:100. When the cocatalyst and themetallocene compound are included at the above weight ratio, activityand a microstructure of the polymer may be optimized.

Meanwhile, as long as the support is a metal, a metal salt, or a metaloxide which is commonly used in supported catalysts, there is nolimitation in the constitution thereof. Specifically, the support mayinclude any support selected from the group consisting of silica,silica-alumina, and silica-magnesia. The support may be dried at a hightemperature. Generally, the support may include an oxide, a carbonate, asulfate, or a nitrate of a metal, such as Na₂O, K₂CO₃, BaSO₄, Mg(NO₃)₂,etc.

An amount of hydroxy groups (—OH) on the surface of the support ispreferably as small as possible, but it is practically difficult toeliminate all hydroxy groups. The amount of hydroxy groups may becontrolled by the preparation method, the preparation conditions, thedrying conditions (temperature, time, drying method, etc.), etc. of thesupport, and the amount is preferably 0.1 mmol/g to 10 mmol/g, morepreferably 0.1 mmol/g to 1 mmol/g, and further preferably 0.1 mmol/g to0.5 mmol/g. In order to reduce a side-reaction by a few hydroxy groupswhich remain after drying, a support, from which hydroxy groups arechemically eliminated while preserving highly reactive siloxane groupsthat participate in supporting, may be used.

The metallocene-supported catalyst according to the present disclosuremay be used as it is in the polymerization of olefinic monomers. Also,the metallocene-supported catalyst according to the present disclosuremay be prepared as a pre-polymerized catalyst by contacting the catalystwith an olefinic monomer. For example, it may be prepared as apre-polymerized catalyst by contacting the catalyst with an olefinicmonomer such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, etc.

The metallocene-supported catalyst according to the present disclosureis prepared, for example, by supporting the cocatalyst compound on thesupport, and supporting the metallocene compound represented by ChemicalFormula 1 or Chemical Formula 2 on the support. Between the respectivesupporting steps, washing with a solvent may be additionally carriedout.

The process of preparing the metallocene-supported catalyst as above maybe carried out at a temperature of about 0° C. to about 100° C. underatmospheric pressure, but is not limited thereto.

Meanwhile, the present disclosure provides a method of preparing apolyolefin by polymerizing olefinic monomers in the presence of themetallocene-supported catalyst, and a polyolefin prepared by the abovepreparation method.

The olefinic monomer may include ethylene, alpha-olefin, cyclic olefin,diene olefin, or triene olefin having two or more double bonds.

Specific examples of the olefinic monomer may include ethylene,propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene,1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene,1-eicosene, norbornene, norbornadiene, ethylidenenorbornene,phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene,1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene,divinylbenzene, 3-chloromethylstyrene, etc., and these monomers may becopolymerized by mixing two or more thereof.

The polymerization reaction may be carried out by a solutionpolymerization process, a slurry process, or a gas phase process usingone continuous slurry polymerization reactor, loop slurry reactor, gasphase reactor, or solution reactor. Further, the polymerization reactionmay be carried out by homopolymerizing one type of olefinic monomer orcopolymerizing two or more types of monomers.

The metallocene-supported catalyst may be injected after being dissolvedor diluted in an aliphatic hydrocarbon solvent having 5 to 12 carbonatoms, for example, pentane, hexane, heptane, nonane, decane, andisomers thereof, an aromatic hydrocarbon solvent such as toluene andbenzene, or a hydrocarbon solvent substituted with a chlorine atom suchas dichloromethane and chlorobenzene. The solvent is used, preferably,after removing a small amount of water, air or the like acting as acatalyst poison by treatment of a small amount of alkyl aluminum. It isalso possible to use an additional cocatalyst.

The polymerization of the olefinic monomer may be carried out at atemperature of about 25° C. to about 500° C. and a pressure of about 1kgf/cm² to about 100 kgf/cm² for about 1 hr to about 24 hrs.Specifically, the polymerization of the olefinic monomer may be carriedout at a temperature of about 25° C. to about 500° C., preferably about25° C. to about 200° C., and more preferably about 50° C. to about 100°C. Furthermore, the reaction pressure may be about 1 kgf/cm² to about100 kgf/cm², preferably about 1 kgf/cm² to about 50 kgf/cm², and morepreferably about 5 kgf/cm² to about 40 kgf/cm².

The metallocene-supported catalyst of the present disclosure mayeffectively polymerize olefinic monomers with very excellent activity.Particularly, the activity of the metallocene-supported catalyst may be3.6 kg/gCat·hr or more, or 3.6 kg/gCat·hr to 30 kg/gCat·hr, preferably,3.85 kg/gCat·hr or more or 3.9 kg/gCat·hr or more, and more preferably,4.3 kg/gCat·hr or more, as calculated by a ratio of the weight (kg) ofthe produced polymer per unit weight (g) of the used catalyst per unittime (hr).

According to an embodiment of the present invention, a highly efficientcatalyst having improved activity and bulk density (BD) may be developedby introducing a particular pivalate group into the metallocenecompound. When the metallocene catalyst of the present disclosure isapplied to a polymerization process, economic benefits due to highactivity and productivity improvement due to control of polymermorphology may be expected.

The polyolefin prepared according to the present disclosure may be apolyethylene polymer, but is not limited thereto.

In the case where the polyolefin is an ethylene/alpha-olefin copolymer,a content of alpha-olefin as a comonomer is not particularly limited,and it may be adequately selected according to the use or purpose of thepolyolefin. More specifically, the content may be more than 0 mole % and99 mole % or less.

The prepared polyolefin may have a high molecular weight and a lowmolecular weight owing to relatively high activity and excellentcomonomer reactivity of the catalyst, compared to polyolefins preparedby using an organometallic compound of a similar structure.

According to an embodiment of the present invention, the olefinicpolymer may have a weight average molecular weight (Mw) of about 10,000g/mol to about 2,000,000 g/mol. Here, the olefinic polymer may have amolecular weight distribution (Mw/Mn) of about 1 to about 10, preferablyabout 3 to about 6. Further, the olefinic polymer may a density of 0.910g/mL to 0.960 g/mL.

In particular, the olefinic polymer may have a bulk density (BD) of 0.29g/mL or more, or 0.29 g/mL to 0.35 g/mL, and preferably 0.30 g/mL ormore. Improvement of the bulk density (BD) is associated with settlingefficient (SE) in a slurry process, and SE improvement allowsproductivity improvement and stable process operation. Therefore, it canbe seen that BD improvement is a very important effect.

Hereinafter, preferred examples are provided for better understanding ofthe present disclosure. However, the following examples are provided forillustrative purposes only and the present disclosure is not intended tobe limited by these examples.

EXAMPLE Preparation Example of Metallocene Compound Synthesis Example 1:Precursor A

1-1 Preparation of Ligand Compound

4.05 g (20 mmol) of ((1H-inden-3-yl)methyl)trimethylsilane was injectedinto a dried 250 mL Schlenk flask and dissolved in 40 mL of diethyletherunder an argon atmosphere. After this solution was cooled down to 0° C.,9.6 mL (24 mmol) of 1.2 equivalent weights of 2.5 M n-BuLi dissolved inhexane was slowly added dropwise thereto. This reaction mixture wasslowly warmed up to room temperature, and stirred for 24 hrs. In another250 mL Schlenk flask, a solution was prepared by dissolving 2.713 g (10mmol) of silicone tether in 30 mL of hexane and cooled down to −78° C.,and the above prepared mixture was slowly added dropwise thereto.Thereafter, the mixture was gradually warmed up to room temperature, andstirred for 24 hrs. 50 mL of water was added thereto, and an organiclayer was extracted with 50 mL of ether three times. To the collectedorganic layer, an appropriate amount of MgSO₄ was added, stirred for awhile, and filtered, and the solvent was dried under reduced pressure.As a result, 6.1 g (molecular weight: 603.11, 10.05 mmol, yield: 100.5%)of a ligand compound in the form of a yellow oil was obtained. Theobtained ligand compound was used in the preparation of metallocenecompounds without further separation procedure.

¹H NMR (500 MHz, CDCl₃): 0.02 (18H, m), 0.82 (3H, m), 1.15 (3H, m), 1.17(9H, m), 1.42 (H, m), 1.96 (2H, m), 2.02 (2H, m), 3.21 (2H, m), 3.31(1H, s), 5.86 (1H, m), 6.10 (1H, m), 7.14 (3H, m), 7.14 (2H, m) 7.32(3H, m).

1-2 Preparation of Metallocene Compound Precursor

The ligand compound synthesized in 1-1 was added to a 250 mL Schlenkflask dried in an oven, and then dissolved in 4 equivalent weights ofmethyl tert-butyl ether and 60 mL of toluene, to which 2 equivalentweights of n-BuLi hexane solution was added for lithiation. After oneday, all solvent in the flask was removed under a vacuum condition, andthe resultant was dissolved in an equal amount of toluene. Also, in aglove box, one equivalent weight of ZrCl₄(THF)₂ was added in a 250 mLSchlenk flask, and then toluene was injected into the flask to prepare asuspension. The above two flasks were cooled down to −78° C., and thenthe lithiated ligand compound was slowly added to the toluene suspensionof ZrCl₄(THF)₂. After completion of the injection, the reaction mixturewas slowly warmed up to room temperature, stirred for one day andallowed to carry out the reaction. Then, toluene in the mixture wasremoved to a volume of about 1/5 through vacuum decopression. Hexane ofabout 5 times the volume of the remaining toluene was added thereto andthe mixture was recrystallized. The resultant was filtered withoutcontacting with the outside air to give a metallocene compound. Theresulting filter cake in the upper portion of the filter was washedusing a small amount of hexane, and then weighed in the glove box toidentify the synthesis, yield, and purity.

As a result, 7.3 g (9.56 mmol, 95.6%) of a purple oil was obtained from6.1 g (10 mmol) of the ligand compound, and was stored in a toluenesolution (purity: 100%, molecular weight: 763.23).

¹H NMR (500 MHz, CDCl₃): 0.03 (18H, m), 0.98, 1.28 (3H, d), 1.40 (9H,m), 1.45 (4H, m), 1.66 (6H, m), 2.43 (4H, s), 3.47 (2H, m), 5.34 (1H,m), 5.56 (1H, m), 6.95 (1H, m), 6.97 (1H, m), 6.98 (1H, m), 7.22 (1H,m), 7.36 (2H, m), 7.43 (1H, m), 7.57 (1H, m)

1-3 Preparation of Metallocene Compound

1.52 g (2 mmol) of the metallocene compound precursor prepared in 1-2was added to a 250 mL Schlenk flask dried in an oven, and then dilutedwith 40 mL of dry toluene. This solution was cooled down to −78° C., andthen 840 mg (6 mmol, 3 equivalent weights) of potassium pivalate wasadded thereto under an argon atmosphere. When this reaction mixture wasgradually warmed up to room temperature, the color of the solutionchanged from red to yellow as the reaction proceeded. This reactionmixture was further stirred for about 2 hours, and then passed through acelite pad under an argon atmosphere to remove the residual potassiumpivalate and inorganic materials. A solvent was removed from a filtrateunder reduced pressure to obtain a light yellow compound with a yield of80%.

¹H NMR (500 MHz, CDCl₃): 0.05-0.24 (18H, m), 0.89-0.92 (3H, m),1.28-1.43 (31H, m), 1.50-1.62 (4H, m), 2.17-2.23 (2H, m), 2.46 (4H, s),3.34 (2H, m), 6.32 (2H, m), 6.67 (2H, m), 7.14-7.38 (8H, m)

Synthesis Example 2: Precursor B

As a metallocene compound precursor,dichloro[rac-ethylenebis(4,5,6,7-tetrahydro-1-indenyl)]zirconium(IV) wasprocured (purchased from Sigma-Aldrich, Cas Number 100163-29-9). 2.13 g(5 mmol) of the metallocene compound precursor was added to a 250 mLSchlenk flask dried in an oven. Under an argon atmosphere, 1.02 g (10mmol) of pivalic acid was added thereto, and dissolved in 50 mL ofdichloromethane. This reaction mixture was cooled down to 0° C., andthen 1.4 mL (10 mmol) of triethylamine was slowly injected thereto. Abath was removed, and the reaction mixture was gradually warmed up toroom temperature. Within 30 minutes, a yellow color disappeared and itturned to a white color. After about 1 hr, the reaction solvent wascompletely removed under reduced pressure, and 100 mL of ether was addedto completely dissolve a white solid by sonication. The mixture in theflask was filtered under an argon atmosphere to obtain a colorless etherfiltrate. This filtrate was completely dried to obtain 2.65 g (yield ofabout 90%) of a white solid.

¹H NMR (500 MHz, CDCl₃): 1.19 (18H, s), 1.41-1.58 (4H, m), 1.72-1.79(2H, m), 1.81-1.88 (2H, m), 2.21-2.25 (2H, m), 2.33-2.39 (2H, m),2.52-2.60 (2H, m), 2.82-2.88 (2H, m), 3.03-3.16 (4H, m), 5.57 (2H, s),5.92 (2H, s)

Synthesis Example 3: Precursor C

As a metallocene compound precursor, dichloro[rac-ethylenebis(indenyl)]zirconium(IV) was procured (purchased from Sigma-Aldrich,CAS Number 100080-82-8). 2.05 g (5 mmol) of the metallocene compoundprecursor was added to a 250 mL Schlenk flask dried in an oven, and then60 mL of dry toluene was added thereto to prepare a suspension. Under anargon atmosphere, 2.11 g (15 mmol, 3 equivalent weights) of potassiumpivalate was thereto, and within about 2 hrs, floating materialsdisappeared, and the solution turned clear yellow. This reaction mixturewas further stirred for about 3 hours, and then passed through a celitepad under an argon atmosphere to remove residual potassium pivalate andinorganic materials. A solvent was removed from a resulting filtrateunder reduced pressure and recrystallized with pentane to obtain a lightyellow compound with a yield of 50% to 60%.

¹H NMR (500 MHz, CDCl₃): 0.98-1.22 (18H, m), 3.34 (4H, s), 6.61 (2H, m),6.83 (2H, m), 7.26-7.35 (4H, m), 7.37-7.41 (2H, m), 7.43-7.48 (1H, m),7.54-7.58 (1H, m)

Comparative Synthesis Example 1: Precursor E

A metallocene compound having the above structural formula,dichloro[rac-ethylenebis(4,5,6,7-tetrahydro-1-indenyl)]zirconium(IV) wasprocured (purchased from Sigma-Aldrich, Cas Number 100163-29-9).

Comparative Synthesis Example 2: Precursor F

A metallocene compound having the above structural formula,dichloro[rac-ethylene bis(indenyl)]zirconium(IV) was procured (purchasedfrom Sigma-Aldrich, CAS Number 100080-82-8).

Comparative Synthesis Example 3: Precursor D

6-1 Preparation of Ligand Compound

4.05 g (20 mmol) of ((1H-inden-3-yl)methyl)trimethylsilane was injectedinto a dried 250 mL Schlenk flask and dissolved in 40 mL of diethyletherunder an argon atmosphere. After this solution was cooled down to 0° C.,9.6 mL (24 mmol) of 1.2 equivalent weights of 2.5 M n-BuLi dissolved inhexane was slowly added dropwise. This reaction mixture was slowlywarmed up to room temperature, and stirred for 24 hrs. In another 250 mlSchlenk flask, a solution was prepared by dissolving 2.713 g (10 mmol)of a silicone tether in 30 mL of hexane and cooled down to −78° C., andthe above prepared mixture was slowly added dropwise thereto.Thereafter, the mixture was gradually warmed up to room temperature, andstirred for 24 hrs. 50 mL of water was added thereto, and an organiclayer was extracted with 50 mL of ether three times. To the collectedorganic layer, an appropriate amount of MgSO₄ was added, and stirred fora while. The mixture was filtered, and the solvent of the filtrate wasdried under reduced pressure. Then, 6.1 g (molecular weight: 603.11,10.05 mmol, yield: 100.5%) of a ligand compound in the form of a yellowoil was obtained. The obtained ligand compound was used in thepreparation of metallocene compounds without a further separationprocedure.

¹H NMR (500 MHz, CDCl₃): 0.02 (18H, m), 0.82 (3H, m), 1.15 (3H, m), 1.17(9H, m), 1.42 (H, m), 1.96 (2H, m), 2.02 (2H, m), 3.21 (2H, m), 3.31(1H, s), 5.86 (1H, m), 6.10 (1H, m), 7.14 (3H, m), 7.14 (2H, m) 7.32(3H, m).

6-2 Preparation of Metallocene Compound

The ligand compound synthesized in 6-1 was added to a 250 mL Schlenkflask dried in an oven, and then dissolved in 4 equivalent weights ofmethyl tert-butyl ether and 60 mL of toluene, to which 2 equivalentweights of n-BuLi hexane solution was added for lithiation. After oneday, all solvent in the flask was removed under a vacuum condition, andthe resultant was dissolved in an equal amount of toluene. Also, in aglove box, one equivalent weight of ZrCl₄(THF)₂ was added in a 250 mLSchlenk flask, and then toluene was injected into the flask to prepare asuspension. The above two flasks were cooled down to −78° C., and thenthe lithiated ligand compound was slowly added to the toluene suspensionof ZrCl₄(THF)₂. After completion of the injection, the reaction mixturewas slowly warmed up to room temperature, stirred for one day andallowed to react. Then, toluene in the mixture was removed to a volumeof about 1/5 through vacuum/reduced pressure. Hexane of about 5 timesthe volume of the remaining toluene was added thereto and the mixturewas recrystallized. The resultant was filtered without contacting withthe outside air to give a metallocene compound. The resulting filtercake in the upper portion of the filter was washed using a small amountof hexane, and then weighed in the glove box to identify the synthesis,yield, and purity.

As a result, 7.3 g (9.56 mmol, 95.6%) of a purple oil was obtained from6.1 g (10 mmol) of the ligand compound, and was stored in a toluenesolution. (purity: 100%, molecular weight: 763.23) ¹H NMR (500 MHz,CDCl₃): 0.03 (18H, m), 0.98, 1.28 (3H, d), 1.40 (9H, m), 1.45 (4H, m),1.66 (6H, m), 2.43 (4H, s), 3.47 (2H, m), 5.34 (1H, m), 5.56 (1H, m),6.95 (1H, m), 6.97 (1H, m), 6.98 (1H, m), 7.22 (1H, m), 7.36 (2H, m),7.43 (1H, m), 7.57 (1H, m)

Comparative Synthesis Example 4: Precursor G

2.13 g (5 mmol) of the precursor D compound of Comparative SynthesisExample 3 was added to a 250 mL Schlenk flask dried in an oven, and thendissolved in a sufficient amount (about 100 mL) of THF. 5 mL (10 mmol)of pentyl magnesium bromide (2.0 M solution in ether) was slowly addedthereto, and then stirred for one day. This reaction mixture wasfiltered under an argon atmosphere to remove a white solid, and aresulting yellow filtrate was dried under reduced pressure, and thenwashed with hexane to obtain a white solid.

¹H NMR (500 MHz, CDCl₃): 1.20 (6H, m), 1.64 (4H, m), 1.92 (4H, m), 2.42(2H, m), 2.63 (2H, m), 2.71 (2H, m), 3.11-3.19 (2H, m), 3.53 (2H, m),5.60 (2H, s), 6.58 (2H, s)

Preparation Example of Supported Catalyst Catalyst Example 1

1.77 g of the catalyst precursor structure A prepared in SynthesisExample 1, 30 mL of toluene, 0.22 g of TIBAL, and 54 g of 10 wt % MAOwere added to a 250 mL Schlenk flask, and then allowed to react at roomtemperature for 15 minutes. 100 mL of toluene was added to a 300 mLglass reactor, 10 g of silica (Grace Davison, SP952X calcined at 200°C.) was added thereto at 40° C., and stirred (500 rpm) for 30 min, andthen allowed to stand. The solution prepared in the 250 mL flask wasadded to a glass reactor, heated to 80° C., and allowed to react for 6hrs while stirring it. The reactor was cooled down to room temperature,and then stirring was stopped, followed by settling for 10 min anddecantation. 100 mL of hexane was injected into the reactor, the hexaneslurry was transferred to a Schlenk flask, and the hexane solution wassubjected to decantation. The resultant was dried at room temperatureunder reduced pressure for 3 hrs.

Catalyst Example 2

A supported catalyst was prepared in the same manner as in CatalystExample 1, except that 0.56 g of the catalyst precursor structure Bprepared in Synthesis Example 2 was used.

Catalyst Example 3

A supported catalyst was prepared in the same manner as in CatalystExample 1, except that 0.55 g of the catalyst precursor structure Cprepared in Synthesis Example 3 was used.

Catalyst Example 4

0.44 g of the catalyst precursor structure A prepared in SynthesisExample 1, 0.42 g of the catalyst precursor structure B prepared inSynthesis Example 2, 30 mL of toluene, 0.22 g of TIBAL, and 54 g of 10wt % MAO were added to a 250 mL Schlenk flask, and then allowed to reactat room temperature for 15 minutes. 100 mL of toluene was added to a 300mL glass reactor, 10 g of silica (Grace Davison, SP952X calcined at 200°C.) was added thereto at 40° C., and stirred for 30 min (500 rpm), andthen allowed to stand. The solution prepared in the 250 mL flask wasadded to a glass reactor, heated up to 80° C., and allowed to react for6 hrs while stirring it. The reactor was cooled down to roomtemperature, and then stirring was stopped, followed by settling for 10min and decantation. 100 mL of hexane was injected to the reactor, thehexane slurry was transferred to a Schlenk flask, and the hexanesolution was subjected to decantation. The resultant was dried at roomtemperature under reduced pressure for 3 hrs.

Catalyst Example 5

100 mL of toluene was injected to a 300 mL BSR (Bench Scale Reactor),and 10 g of silica (Grace Davison, SP952X calcined at 200° C.) was addedthereto at 40° C., and stirred for 30 min (500 rpm). 54 g of 10 wt % MAOwere added thereto, and the temperature was raised up to 70° C., andallowed to react for 12 hrs while stirring it. The reactor was cooleddown to 40° C. and stirring was stopped, followed by settling for 10 minand decantation. 100 mL of toluene was injected into the reactor,followed by stirring for 10 min, settling for 10 min, and decantation.100 mL of toluene was injected thereto, and then 1.77 of the catalystprecursor A prepared in Synthesis Example 1 was mixed with toluene, thismixture was injected to the reactor, and allowed to react while stirring(500 rpm) for 1.5 hrs. The reactor was cooled down to room temperature,and stirring was stopped, followed by settling for 10 min anddecantation. 100 mL of hexane was injected into the reactor, and thehexane slurry was transferred to a Schlenk flask, and the hexanesolution was subjected to decantation. The resultant was dried at roomtemperature under reduced pressure for 3 hrs.

Catalyst Example 6

A supported catalyst was prepared in the same manner as in CatalystExample 5, except that 0.56 g of the catalyst precursor structure Bprepared in Synthesis Example 2 was used.

Comparative Catalyst Example 1

0.43 g of the catalyst precursor structure E prepared in ComparativeSynthesis Example 1, 30 mL of toluene, 0.22 g of TIBAL, and 54 g of 10wt % MAO were added to a 250 mL Schlenk flask, and then allowed to reactat room temperature for 15 minutes. 100 mL of toluene was added to a 300mL glass reactor, 10 g of silica (Grace Davison, SP952X calcined at 200°C.) was added thereto at 40° C., and stirred for 30 min (500 rpm), andthen allowed to stand. The solution prepared in the 250 mL flask wasinjected to a glass reactor, and heated to 80° C., and allowed to reactfor 6 hrs while stirring it. The reactor was cooled down to roomtemperature, and then stirring was stopped, followed by settling for 10min and decantation. 100 mL of hexane was injected into the reactor, thehexane slurry was transferred to a Schlenk flask, and the hexanesolution was subjected to decantation. The resultant was dried at roomtemperature under reduced pressure for 3 hrs.

Comparative Catalyst Example 2

A supported catalyst was prepared in the same manner as in ComparativeCatalyst Example 1, except that 0.42 g of the catalyst precursorstructure F prepared in Comparative Synthesis Example 2 was used.

Comparative Catalyst Example 3

100 mL of toluene was injected to a 300 mL BSR (Bench Scale Reactor),and 10 g of silica (Grace Davison, SP952X calcined at 200° C.) was addedthereto at 40° C., and it was stirred for 30 min (500 rpm). 54 g of 10wt % MAO was injected into the reactor, the temperature was raised up to70° C., and allowed to react for 12 hrs while stirring. The reactor wascooled down to 40° C. and stirring was stopped, followed by settling for10 min and decantation. 100 mL of toluene was injected into the reactor,followed by stirring for 10 min, settling for 10 min, and decantation.0.43 g of the catalyst precursor E prepared in Comparative SynthesisExample 1 was mixed with 100 mL of toluene, and the mixture was injectedinto the reactor. Then, the reactant was stirred for 1.5 hrs (500 rpm).The reactor was cooled down to room temperature, and stirring wasstopped, followed by settling for 10 min and decantation. 100 mL ofhexane was injected into the reactor, the hexane slurry was transferredto a Schlenk flask, and the hexane solution was subjected todecantation. The resultant was dried at room temperature under reducedpressure for 3 hrs.

Comparative Catalyst Example 4

100 mL of toluene was injected into a 300 mL BSR (Bench Scale Reactor),and 10 g of silica (Grace Davison, SP952X calcined at 200° C.) was addedthereto at 40° C., and stirred (500 rpm) for 30 min. 54 g of 10 wt % MAOwas injected thereto, and the temperature was raised up to 70° C., andallowed to react for 12 hrs while stirring. The reactor was cooled downto 40° C. and stirring was stopped, followed by settling for 10 min anddecantation. 100 mL of toluene was injected into the reactor, followedby stirring for 10 min, settling for 10 min, and decantation. 0.34 g ofthe catalyst precursor D prepared in Comparative Synthesis Example 3 wasmixed with 100 mL of toluene, the mixture was injected into the reactor,and allowed to react while stirring for 1.5 hrs. Then, 0.43 g of thecatalyst precursor E prepared in Comparative Synthesis Example 1 wasmixed with 30 mL of toluene, the mixture was added to the reactor, andallowed to react for 1.5 hrs. The reactor was cooled down to roomtemperature, and stirring was stopped, followed by settling for 10 minand decantation. 100 mL of hexane was injected into the reactor, thehexane slurry was transferred to a Schlenk flask, and the hexanesolution was subjected to decantation. The resultant was dried at roomtemperature under reduced pressure for 3 hrs.

Comparative Catalyst Example 5

A supported catalyst was prepared in the same manner as in ComparativeCatalyst Example 3, except that 0.50 g of the catalyst precursorstructure G prepared in Comparative Synthesis Example 4 was used.

Preparation Example of Polyethylene Polymerization PolymerizationExamples 1 to 6 and Comparative Polymerization Examples 1 to 5:Preparation of Polyolefin

Ethylene Polymerization

2 mL of TEAL (1 M in hexane) and 80 g of 1-hexene were injected into a 2L autoclave reactor, to which 0.6 kg of hexene was added and then heatedto 70° C. while stirring at 500 rpm. 21.1 mg to 54.0 mg of the supportedcatalysts (Catalyst Examples 1 to 6 and Comparative Catalyst Examples 1to 5) were placed with hexane in vials, and 0.2 kg of hexane was furtheradded. When the internal temperature of the reactor reached 70° C., thesolution was reacted under an ethylene pressure of 30 bar for 1 hr whilestirring at 500 rpm. Hydrogen was injected at a rate (0.012% to 0.002%)determined according to a flow rate of ethylene. After completion of thereaction, a resulting polymer was filtered to primarily remove hexane,and then dried in oven at 80° C. for 3 hrs.

Particularly, the ethylene polymerization was performed with addition ofhydrogen. A test was performed by varying the feeding amount of hydrogenand the amount of the catalyst in consideration of the activity andmolecular weight during ethylene homopolymerization, hydrogenreactivity, etc. in order to adjust target MI2 in the range of 0.1 to1.0.

In the polymerization process, the catalytic activity and physicalproperties of the resulting polymers were measured by the followingmethods, and the results are shown in the following Table 1.

1) Catalytic Activity

The weight of the produced polymer per unit weight of the catalyst perunit time was measured to determine catalytic activity in thepolymerization process using the metallocene-supported catalyst.

2) MI Measurement

MI 2.16 value of the produced polyolefin was determined in accordancewith American Society for Testing Materials (ASTM) D 1238 at 190° C.under a load of 2.16 kg (unit: g/10 min).

3) BD (Bulk Density) Measurement

A weight of powder filled in a 100 mL container was determined inaccordance with American Society for Testing Materials (ASTM) D 1895 B(unit: g/mL).

The reaction conditions and results of Polymerization Examples 1 to 6and Comparative Polymerization Examples 1 to 5 are summarized in thefollowing Table 1.

TABLE 1 Content of Catalyst catalyst Activity H₂ feed Ml_2.16 BD(structure) (mg) (kgPE/gCat) (mol %) (g/10 min) (g/mL) olymerizationExample 1 21.1 5.5 0.02 0.72 0.29 Example 1 (A) Polymerization Example 249.5 4.3 0.10 0.12 0.30 Example 2 (B) Polymerization Example 3 29.8 3.60.03 0.48 0.29 Example 3 (C) Polymerization Example 4 40.0 4.8 0.07 0.400.30 Example 4 (A/B) Polymerization Example 5 23.9 4.6 0.02 0.75 0.29Example 5 (A) Polymerization Example 6 54.0 3.9 0.10 0.15 0.30 Example 6(B) Comparative Comparative 50.1 3.0 0.10 0.22 0.28 PolymerizationExample 1 Example 1 (E) Comparative Comparative 30.2 2.5 0.03 0.50 0.27Polymerization Example 2 Example 2 (F) Comparative Comparative 48.8 3.40.10 0.20 0.27 Polymerization Example 3 Example 3 (E) ComparativeComparative 43.1 3.8 0.07 0.53 0.27 Polymerization Example 4 Example 4(D/E) Comparative Comparative 37.2 2.0 0.12 0.30 0.28 PolymerizationExample 5 Example 5 (G) Polymerization conditions: ethylene pressure of30 bar, temperature of 70° C. ° reaction time of 60 min.

As shown in Table 1, the present disclosure provides an excellent effectthat the polyolefin produced with high catalytic activity during olefinpolymerization has high bulk density (BD). Therefore, improvement ofproductivity due to high bulk density may be achieved by using themetallocene-supported of the present disclosure.

When the supported catalyst having a pivalate group as a substituentaccording to the present invention was used as in Polymerization Example6, catalytic activity was 3.9 kg PE/gCat and bulk density (BD) was 0.30g/mL. In contrast, when the supported catalyst having a pentyl group asa substituent was used as in Comparative Polymerization Example 5,catalytic activity and bulk density (BD) were as remarkably low as 2.0kgPE/gCat and 0.28 g/mL, respectively. Further, Polymerization Examples1 and 2 showed excellent catalytic activity of 5.5 kgPE/gCat and 4.3kgPE/gCat, and excellent bulk density (BD) of 0.29 g/mL and 0.30 g/mL,respectively. Furthermore, Polymerization Example 4 according to thepresent disclosure showed catalytic activity of 4.8 kgPE/gCat and bulkdensity (BD) of 0.30 g/mL, whereas Comparative Polymerization Example 4showed catalytic activity of 3.8 kgPE/gCat and bulk density (BD) of 0.27g/mL, indicating remarkable improvement in Polymerization Example 4.

Accordingly, when the metallocene-supported catalyst having theparticular substituent according to the present disclosure is used,remarkably improved catalytic activity may be obtained even by using thedifferent supporting method as in Polymerization Examples 1 and 3.

1. A metallocene-supported catalyst comprising one or more metallocenecompounds represented by the following Chemical Formula 1 or ChemicalFormula 2; a cocatalyst compound; and a support:

wherein, in Chemical Formula 1, R₁ and R₂, and R₅ and R₆, are the sameas or different from each other, and are each independently hydrogen ora C1 to C20 alkyl group; R₃ and R₄, and R₇ and R₈, are the same as ordifferent from each other, and are each independently hydrogen or a C1to C20 alkyl group, or two or more neighboring groups of R₃ and R₄, andR₇ and R₈, are connected to each other to form a substituted orunsubstituted aliphatic or aromatic ring; Q is a Group 4 transitionmetal; and R₉ and R₁₀ are the same as or different from each other, andare each independently a C1 to C20 alkylate group,

wherein, in Chemical Formula 2, M is a Group 4 transition metal; B iscarbon, silicon, or germanium; Q₁ and Q₂ are the same as or differentfrom each other, and are each independently hydrogen, a halogen, a C1 toC20 alkyl group, a C2 to C20 alkenyl group, a C6 to C20 aryl group, a C7to C20 alkylaryl group, a C7 to C20 arylalkyl group, a C1 to C20 alkoxygroup, a C2 to C20 alkoxyalkyl group, a C3 to C20 heterocycloalkylgroup, or a C5 to C20 heteroaryl group; X₁ and X₂ are the same as ordifferent from each other, and are each independently a C1 to C20alkylate group; and C₁ and C₂ are the same as or different from eachother, and are each independently represented by any one of thefollowing Chemical Formula 3a, Chemical Formula 3b, Chemical Formula 3c,and Chemical Formula 3d, provided that one or more of C₁ and C₂ arerepresented by Chemical Formula 3a:

wherein, in Chemical Formulae 3a, 3b, 3c, and 3d, R₁ to R₂₈ are the sameas or different from each other, and are each independently hydrogen, ahalogen, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C1 to C20alkylsilyl group, a C1 to C20 silylalkyl group, a C1 to C20 alkoxysilylgroup, a C1 to C20 ether group, a C1 to C20 silylether group, a C1 toC20 alkoxy group, a C6 to C20 aryl group, a C7 to C20 alkylaryl group,or a C7 to C20 arylalkyl group, R′₁ to R′₃ are the same as or differentfrom each other, and are each independently, hydrogen, a halogen, a C1to C20 alkyl group, a C2 to C20 alkenyl group, or a C6 to C20 arylgroup, and two or more neighboring groups of R₁ to R₂₈ are connected toeach other to form a substituted or unsubstituted aliphatic or aromaticring.
 2. The metallocene-supported catalyst of claim 1, wherein R₉ andR₁₀ of Chemical Formula 1 or X₁ and X₂ of Chemical Formula 2 are amethylate group, an ethylate group, a propylate group, or a pivalategroup.
 3. The metallocene-supported catalyst of claim 1, wherein thecompound represented by Chemical Formula 1 is any one of the followingstructural formulae:


4. The metallocene-supported catalyst of claim 1, wherein the compoundrepresented by Chemical Formula 2 has the following structural formula:


5. The metallocene-supported catalyst of claim 1, wherein the catalystcompound comprises one or more of compounds represented by the followingChemical Formula 4, Chemical Formula 5, and Chemical Formula 6:—[Al(R₂₃)—O]_(n)—  [Chemical Formula 4] wherein, in Chemical Formula 4,each R₂₃ is the same as or different from each other, and are eachindependently a halogen, a C1 to C20 hydrocarbon, or ahalogen-substituted C1 to C20 hydrocarbon; and m is an integer of 2 ormore;J(R₂₃)₃  [Chemical Formula 5] wherein, in Chemical Formula 5, each R₂₃is the same as defined in Chemical Formula 4; and J is aluminum orboron;[E-H]⁺[ZA′₄]⁻ or [E]⁺[ZA′₄]⁻  [Chemical Formula 6] wherein, in ChemicalFormula 6, E is a neutral or cationic Lewis acid; H is a hydrogen atom;Z is Group 13 element; and each A is the same as or different from eachother, and are each independently a C6 to C20 aryl group or a C1 to C20alkyl group, of which one or more hydrogen atoms are unsubstituted orsubstituted with a halogen, a C1 to C20 hydrocarbon, an alkoxy, or aphenoxy.
 6. The metallocene-supported catalyst of claim 1, wherein thesupport is one or more selected from the group consisting of silica,silica-alumina, and silica-magnesia.
 7. The metallocene-supportedcatalyst of claim 1, wherein a weight ratio of the total transitionmetals in the metallocene compound to the support is 1:10 to 1:1000. 8.The metallocene-supported catalyst of claim 1, wherein a weight ratio ofthe cocatalyst compound to the support is 1:1 to 1:100.
 9. A method ofpreparing a polyolefin, which comprises polymerizing olefinic monomersin the presence of the metallocene catalyst of claim
 1. 10. The methodof claim 9, wherein the polymerization is performed by a solutionpolymerization process, a slurry process, or a gas phase process. 11.The method of claim 9, wherein the olefinic monomer comprises one ormore monomers selected from the group consisting of ethylene, propylene,1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene,1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene,1-eicosene, norbornene, norbornadiene, ethylidenenorbornene,phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene,1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene,divinylbenzene, and 3-chloromethylstyrene.
 12. A polyolefin prepared bythe preparation method of claim
 9. 13. The polyolefin of claim 12,wherein a weight average molecular weight is 10,000 g/mol to 1,000,000g/mol.